fix(scala#18265): crash on extension method without body

This commit fixes a bug that causes Scala compiler to crash due to position error when an extension method folowed by a newline has neither type annotation nor `= <expr>`.
i10416 · Oct 22, 2023 · f55e0cd · f55e0cd
1 parent 89a8fce
commit f55e0cd
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diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -2577,6 +2577,8 @@ object Parsers {
       parents match {
         case parent :: Nil if !in.isNestedStart =>
           reposition(if (parent.isType) ensureApplied(wrapNew(parent)) else parent)
+        case tkn if in.token == INDENT =>
+          New(templateBodyOpt(emptyConstructor, parents, Nil))
         case _ =>
           New(reposition(templateBodyOpt(emptyConstructor, parents, Nil)))
       }

diff --git a/tests/neg/i18265.check b/tests/neg/i18265.check
@@ -0,0 +1,6 @@
+-- [E019] Syntax Error: tests/neg/i18265.scala:5:13 --------------------------------------------------------------------
+5 |    def twice // error
+  |             ^
+  |             Missing return type
+  |
+  | longer explanation available when compiling with `-explain`
diff --git a/tests/neg/i18265.scala b/tests/neg/i18265.scala
@@ -0,0 +1,5 @@
+trait Foo
+
+val foo = new Foo:
+  extension (s: String)
+    def twice // error